1. Field of the Invention
The present invention relates to a bass reflex type loudspeaker apparatus and a loudspeaker box thereof, particularly to ones suitable when a loudspeaker box is made thin. Further, the present invention relates to an image display apparatus in which the bass reflex type loudspeaker apparatus is installed.
2. Description of the Related Art
As a kind of loudspeaker apparatus, a bass reflex type loudspeaker apparatus has been used widely. A bass reflex type loudspeaker apparatus has been known as the one in which a duct is provided in a loudspeaker box for emitting a sound generated from the back surface of a loudspeaker unit to the outside. Since a sound generated from the back surface of the loudspeaker unit is detoured in the duct to be emitted to the outside, the phase of a sound in a low frequency range is reversed (specifically, a low sound generated from the back surface of the loudspeaker unit is made to have the same phase as a low sound generated from the front surface of the loudspeaker unit), and the characteristic of a low sound range can be improved.
Typically, a bass reflex type loudspeaker apparatus in related art has a duct in pipe shape (cylindrical shape) whose route linearly extends as a bass reflex duct in a loudspeaker box (see Patent Literature 1 and 2, for example).
[Patent Literature 1] Japanese Published Patent Application No. 2003-61177 (paragraph 0007, FIG. 1)
[Patent Literature 2] Japanese Published Patent Application No. 2003-324795 (paragraphs 0064, 0077 to 0079, FIG. 3)